Making secure routers with opensource firmware

In Turris, we are making routers. They come with root account, open source firmware, security updates and repositories full of aditional open source software. Why? We think that it is the right way to do modern electronics - devices should be completelly under control of their users and secure. How hard it is? What are the advantages and disavantages of this approach for us - the makers of those routers? On the other hand, what does it bring our users apart from freedom? What interesting software do we integrate and what crazy stuff do people do with our router?